The effects of hormones and nutrients on apolipoprotein metabolism will be examined by using three major animal models: (1) rat, (2) dog, and (3) patas monkey. The use of the three animal models will afford information on specific effects for the species versus general effects in mammalian lipoprotein physiology. The apolipoprotein and lipid composition of blood and peripheral lymph will be studied to determine the relationship between hormones, nutrients and lipoprotein metabolism in these media. Investigations of the processes will be conducted in animals with in vitro enzyme assays, liver perfusions, and cultured hepatocytes. New techniques in immunochemistry will be utilzed to expand our capabilities to study lipoprotein composition, metabolism and structure. These studies will provide a better understanding of the relationship between hormones, nutrients, and apolipoprotein metabolism in the blood and lymph. These results will help in our understanding of the development of atherosclerosis, its prevention and its treatment.